1. Field of the Invention
The present invention relates generally to strollers or carriages for carrying a child, and more particularly to a stroller adapted to carry a child while a person pushing the stroller is walking or running, and which is adjustable in length from a first operable position primarily for walking in confined places to a second relatively longer operable position primarily for walking or running, and is further adjustable to a collapsed position.
2. Discussion of the Prior Art
Strollers or carriages have long been used to carry small children. Such strollers comprise numerous configurations, generally with an intention of serving one of two purposes: a) to transport a child while the stroller operator primarily engages in activities at a normal walking pace, or as a more recent development b) to transport a child while the stroller operator engages in fitness activities such as brisk walking, jogging, or running.
Generally strollers intended for walking activities are constructed with four individual or pair of relatively small diameter wheels for use at a normal walking pace over relatively smooth surfaces. The four wheels may be mounted on casters and are typically spaced apart in a compact, relatively short wheelbase, with a relatively narrow track.
In contrast, strollers intended for fitness activities are typically constructed with three larger diameter wheels having pneumatic tires and a common fixed directional orientation as opposed to casters. In addition, fitness strollers tend to have a wider track between the rear wheels, and an elongate wheelbase for more stable use at faster paces and over a greater variety of surfaces.
Both types of strollers typically embody an operable position for use and an inoperable collapsed position for transportation or storage.
Heretofore, operators using walking strollers have recognized benefits and drawbacks of such devices. Walking strollers facilitate ease of mobility in more confined places, relative compactness upon folding for more convenient transportation and storage, and may include a child carrier which is adapted to carry a child in an upright, reclined or supine position. However, the small, solid wheels are greatly impacted by surface imperfections, resulting in a firm ride and difficulty in traversing bumpy surfaces or obstacles. Moreover, the small wheels and single operable short wheelbase are not suited for the faster pace of fitness activities.
Examples of collapsible walking strollers having four sets of wheels and more than one seating position are depicted in U.S. Pat. Nos. 4,741,551, and 4,836,573.
Operators using fitness type strollers have recognized particular benefits and drawbacks of such strollers as well. Whether walking at a normal pace or engaging in faster paced fitness activities, the larger wheels with pneumatic tires provide a softer ride with lower rolling resistance and improved ability to traverse surface imperfections or obstacles. The longer wheelbase enhances stability and provides improved ability to track in a straight line.
However, fitness strollers with an elongate wheelbase are generally too long in their operable position to walk in confined places, such as store aisles, and often are not compact enough in their collapsed position for easy transportation or storage. Fitness strollers often have a child seat relatively high above the ground, resulting in the need for a wide track to maintain reasonable stability. The wide track and elongate wheelbase make walking in confined places or competing in crowded organized running events more cumbersome. Also, fitness strollers generally have a child seat that provides either an inclined or upright seating position intended for use at faster paces and over a variety of surfaces. This type of seat is not compatible with carrying a newborn or infant child lacking the physical maturity to sit or hold its head upright.
Examples of three-wheeled fitness strollers are disclosed in U.S. Pat. Nos. 5,364,119, 5,356,171, 5,301,963, 5,299,825, 5,123,670, and 5,029,891.
In view of the great differences between these two general types of strollers, a consumer wishing to carry a child in a stroller, at times, while walking in confined places, and at other times, while engaging in faster paced activities in open areas, must purchase both a walking stroller and a fitness stroller and use them independently. This is an expensive and inconvenient way to enjoy the benefits of the two types of strollers presently sold.
Given the above disadvantages of the prior art, it is a principal object of the present invention to provide a single multi-functional convertible child stroller which provides a more economical and efficient alternative to purchasing and storing two strollers having different intended uses.
Accordingly, it is an object of the present invention to provide a stroller which is adapted to carry a child while a person pushing the stroller is walking or running, and which is adjustable in length from a first operable position primarily for walking in confined places to a second relatively longer operable position primarily for walking or running.
More particularly, the present invention provides a stroller which has an elongate wheelbase, large diameter wheels and pneumatic tires for improved stability, ride and rolling resistance. The stroller provides the unique advantage of being adjustable to a relatively shorter wheelbase for improved mobility in confined places, while still employing large diameter wheels and pneumatic tires for improved ride and rolling resistance.
A stroller of the present invention would enable a user to select a shorter wheelbase for use while engaging in fitness activities when a shorter wheelbase may be desirable, such as during an organized, heavily attended running event.
Another object of the invention is to provide a stroller which has an adjustable handle extension length to provide increased distance between the stroller user and the rear of the stroller when the stroller is used primarily for running.
A further object of the invention is to provide a stroller which can be adapted to carry a child in a sitting position or in a supine position.
Yet another object of the invention is to provide a stroller having relatively few parts which can be collapsed in height, length, and width for storage or transportation.
Still another object of the present invention is to provide a stroller which has a relatively low center of gravity when carrying a child, permitting a narrower track between the rear wheels for improved mobility and storage.